Alert archive / Tennessee / Mesoscale Discussions in 2013

Mesoscale Discussion 87

January 30, 201323 counties in Alabama; 26 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 30, 2013, 1:31 AM CST for 23 counties in Alabama; 26 counties in Tennessee. It was in force for 29 min.

The area

The outline as issued.

The facts

Issued
Jan 30, 2013, 1:31 AM CST (07:31 UTC)
Expired
Jan 30, 2013, 2:00 AM CST
In force
29 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 49 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Talladega County, AL, Walker County, AL, Winston County, AL, Bedford County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Jackson County, TN, Lincoln County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, Moore County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 83 km from the middle of the area, began a volume at 07:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 7.5 hours before the alert went out and 150 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2013-01-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 216 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2013-01-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 254 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
216 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
770 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
254 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 29, 9:49 PM CSTMesoscale DiscussionSPCColbert, Franklin, Lauderdale116 min
Jan 30, 1:46 AM CSTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 16 more8 hr
Jan 30, 4:27 AM CSTMesoscale DiscussionSPCMobile, Washington93 min
Jan 30, 5:01 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Bullock, Butler, Calhoun, Chambers and 26 more29 min
Jan 30, 5:15 AM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 34 more7 hr
Jan 30, 7:43 AM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Calhoun and 36 more62 min
Jan 30, 10:09 AM CSTMesoscale DiscussionSPCBarbour, Bullock, Chambers, Clay, Cleburne, Crenshaw and 9 more96 min
Jan 30, 11:50 AM CSTMesoscale DiscussionSPCBullock, Chambers, Elmore, Lee, Macon, Montgomery and 3 more85 min
Jan 30, 12:19 PM CSTTornado WatchSPCBarbour, Bullock, Butler, Chambers, Coffee, Conecuh and 16 more9 hr
Jan 29, 7:31 PM CSTMesoscale DiscussionSPCChester, Crockett, Fayette, Hardeman, Haywood, Lauderdale and 4 more119 min
Jan 29, 10:07 PM CSTTornado WatchSPCBenton, Carroll, Cheatham, Chester, Davidson, Decatur and 20 more6 hr
Jan 30, 3:03 AM CSTMesoscale DiscussionSPCBenton, Cheatham, Chester, Davidson, Decatur, Dickson and 16 more57 min
Jan 30, 4:51 AM CSTTornado WatchSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Carter and 27 more7 hr
Jan 30, 6:38 AM CSTMesoscale DiscussionSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Carter and 27 more97 min

Nearby

Mesoscale Discussions in Tennessee, 2013Mesoscale Discussions in Alabama, 2013Every mesoscale discussion in 2013

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.